The Debian-Live approach also provides some good opportunities. First and foremost, the very easy remastering makes it efficient to run with no persistent store quite often. For instance, upon remastering, I just start without the store, and the image I run is union-mounted with the persistence file and copied&compressed. Then I have to boot something else to copy the new squashfs image in place, but that's all that has to be done outside the system.
Boot the new image without persistence, create a new persistence file.
For further adaptations, the new persistence file can be mounted in an instance run under kvm, programs can be added and settings tweaked for an eventual new remastering.
Storing the series of squashfs-compressed images, one can always go back in this process if needed.
DELL PowerEdge R730XD Server 2x E5-2697v4 2.3GHz =36 Cores 64GB H730 4xRJ45
$407.00
DELL PowerEdge R630 8SFF Server 2x E5-2650v4 2.2GHz =24 Cores 32GB H730 4xRJ45
$240.00
DELL PowerEdge R630 8SFF Server 2x E5-2680v3 2.5GHz =24 Cores 32GB H730 4xRJ45
$230.00
Dell PowerEdge R710 2.5" 2U Server 2x X5670 2.93GHZ 12-Core 128gb 2x 1TB SAS
$114.99
Dell PowerEdge R620 Server 2x E5-2660 v2 2.2GHz 20 Cores 256GB RAM 1x 480GB SSD
$139.99
HP Proliant DL360 G9 2x2.6GHz Intel 14 Core Xeon E5-2697v3, 32GB RAM, NO HDD
$139.99
Cisco UCS C220 M3 1U 2x 6-Core Xeon E5-2620 2.0GHz / 64GB RAM / No HDD
$89.99
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
1U BareMetal pfsense opnsense Router Firewall DNS Server 6x 10GB Ethernet Ports
$149.00
1U Supermicro Server X10DRU-i+ 2x Xeon Total 36 Cores 64GB 4x 10GBE-T 2PS
$333.00